Boiler



1 mg". 29, 193$ R. M. QSTEREVQZ NN BOILER Filed Dec. 17, 1931 4Sheets-Sheet l Wfirfermannz INVENTOR aim ATTORNEY Aug. 29, 1933. RQSTERMANN 1,924,877

BOILER Filed Dec. 17, 1931 4 Sheets-Sheet 2 R YGJIErmQ/In/ INVENTOR BY Q9M ATTORNEY 1933- R. M. OSTERMANN BOILER Filed Dec. 17, 1931 4Sheets-Sheet 3 INVENTOR ATTORNEY 1933- R. M. OSTERMANN 1,924,877

BOILER Filed Dec. 17, 1931 4 Sheets-Sheet 4 RAAflJ/zrmanw INVENTOR BY617m ATTORNEY Patented Aug. 29, 1933 UNiTi li STATES BOILER Rudolf M.Ostermann, Kenilworth, 111., assignor to The superheater Company, NewYork, N. Y.

Application December 1'7, 1931 Serial No. 581,577

10 Claims. (01. 122-481) This invention relates to boilers equipped withsuperheaters, particularly boilers in which the fire-box is enclosed bywater-cooled surfaces as in the case of the ordinary locomotive boiler.The purpose of the invention is to provide a superheater in such aboiler which will furnish steam of the high superheat desired in modernpractice and yet protect the superheater against excessive heatingparticularly at times when no steam is flowing through it. v

The invention is illustrated in the accompanying drawings. In thesedrawings Fig. l represents a vertical longitudinal section or" alocomotive with my invention applied. Fig. 2 shows at the left a sectionon line 2-2 of Fig. 1 and at the right a fragmentary top View of Fig. 1.Fig. 3 shows at the left a section on line 3a-3a of Fig. l and at theright a section of the same figure on line 317-319. Fig. 4 is anenlargedsection on line 4-4 of Fig. 1. Fig. 5 shows one of the elementsof the superheater according to my invention, the left hand portion ofit being shown in vertical section, on line 5-5 of Fig. 4, this partalso showing the means of securing the unit to the crown sheet of theboiler. Fig. 6 is a section on line 6-6 of Fig. 5. Fig. 7 is a verticallongitudinal section of the rear portion of a locomotive boiler with myinvention, in modified form, in place. Fig. 8 is an outside half-view ofFig. 7 looking toward the right. Fig. 9 is a half-section on line 9-9 ofFig. '7. Figs. 10 and 11 are respectively sections on lines 10-10 and11-11 of Fig. 8. Fig. 12 is an enlarged fragmentary view of one of thesuperheater elements bringing out particularly the means of attachmentof the element to the crown sheet; and Fig. 13 is a section on line13-13 of Fig. 12.

The locomotive boiler shown in Fig. 1 for the purpose of illustrating myinvention is or" the ordinary type. It comprises the fire-box 1 which issurrounded on all sides except the bottom by Water-cooled surfaces. Thecrown sheet 2 defines the top of the fire-box, this crown sheet beingextended downward at the sides as at 3 (Fig. 4) to form the inner sidesof the fire-box. From the rear flue sheet 4 extend forward the fines5-5, their front ends being secured to the front flue sheet 6. Thesefiues open into the smoke-box '7. The gases coming from the firebox 1pass through the flues 5-5 into the smokebox 7 and finally out throughthe smoke stack 8.

The ordinary superheater as used almost universally today comprisestubular elements whose 55 ends are connected to a superheater header,the

header being located in the smoke-box and the tubular elements extendinginto the flues toward the fire-box and to a point in proximity to therear flue sheet. With such superheaters the amount of superheat that canbe obtained has a rather definite limit and when higher tempera- 0 turesare desired, further provisions for superheating must be made. I proposeto do this by locating some of the superheating surface or, in somecases, perhaps all of the superheating surface in the fire-box. In theform of my invention illustrated in Figs. 1 to 6, I combine such afirebox superheater with a flue superheater of the old type. In thesecond form of my invention illustrated in Figs. 7 to 13, thesuperheating surface in the fire-box may be the only superheating 7surface on the locomotive although here too it may, if desired, becombined with superheating surface placed in the fines.

Referring first to the form of the invention illustrated in Figs. 1 toG, I show some superheating elements designated by the reference numeral9, these units of elements being of an ordinary form and extending intosome of the fiues 5-5. The forward ends of the elements are connected tothe superheater header 1%. This portion of the 30 header to which theelements 9-9 are connected resembles the ordinary superheater header inalmost universal use in this country today. A transverse chamber 11 isin communication with the steam space of the boiler by means of the pipe12 and the connecting neck 13. From the transverse chamber 11 extendbackward the fingers or subsidiary headers 14-14:. (See Fig.2).Alternating with these subsidiary headers 14-14 are subsidiary headersor fingers 15-15 which communicate with the transverse chamber 16. Eachsuperheater unit or element 9 has one of its ends connected to a chamberI l and its other end to a chamber 15. Steam therefore flows throughthese elements in parallel from chamber 11 and subsidiary headers 14-44to be delivered by the elements to the subsidiary headers 15-15 and soto the transverse chamber 16.

To the transverse chamber 16 are secured the first ends of a series offurther superheater ele ments 17-17. The other ends of these unitsorelements are connected to a transverse chamber 18. From this chamber 18extend the steam pipes 19-19 which carry the steam to the steam chests.

The elements 17-17 are, in the form of the invention shown in Figs. 1 to6, of the so-called Field-tube type. They extend into and through someof the fines 5, the flues through which they extend being located alongthe top and sides of the total group of flues. As will be seen from aninspection of Fig. 1, these units 17 extend to a point in the vicinityof the rear end of the firebox. Steam from chamber 16 flows through theinner tube 21 (see Fig- 5) to the rear end of each unit, this rear endbeing open as at 22. The outer tube is closed at the rear end by a capas shown at The steam returns toward the front through the annular spacebetween the inner and outer tubes. At the front it is delivered by meansof the end 26 to the chamber 18. Thence, as stated above, it flows tothe steam chest.

It will be noted from what has been said above that the steam flowsfirst through the units 9-9 and after having there been superheated,flows next through the units 17-17, where it is given its final highsuperheat. The portion of the units 17i which lies the fire box isexposed to a very tense radiant heat and does a large pro portion of thesuperheatin This location is of course an extremely hazardous one andunless the heat delivered to this portion of the elements is carried offrapidly, these portions will be overheated and fail. It is for thisreason that the number of the elements 1717 is in practice made smallerthan the nui'nber of the elements 99, so that the iiowof the steamthrough the elements 17-17 is more rapid and the heat transfercorrespondingly enhanced.

As long as a sufficient amount of steam flows through these elements, noadditional protection might be needed. The heat absorption by the steamwould in the majority of cases be sufficient to keep the temperature ofthe metal below the danger point. In locomotive practice, however, thesteam flow is of necessity shut off periodically and during such peri cswhen no steam flow occurs through the elements, further protection forthe radiant part of the elements i717 must be provided. This I do bymeans illustrated more clearly in Figs. 4, 5 and 6. These means have thefurther function of supporting the portion of the superieater elementsextending into the furnace. Th s protecting and supporting provisionconsists essentially of metallic ribs or webs 27. There is one such ribfor each superheater ele ment, the rib being arran ed parallel to theelement and between it and the adjacent fire-box sheet. One edge of eachrib 2"! is secured, as by elding 28, to the sheet. The other edge ispreferably provided with a dove-tail slot 29 (see Fig. 6). Into thisdove-tail slot fits shdably the tongue 36 which is integral with orwelded to the outer tube of theelement. The fit of the tongue A0 30 inthe dove-tail groove 29 is made close so that good heat transfer fromone to the other can occur.

Preferably each rib is made in sections separated by spaces as 31-31(Fig. 1).

By these means the portions of the elements eX- tending into thefire-box are securely supported and protected against overheating. Theheat absorbed by the outer tube 23 at times when no steam is flowingthrough the elements is transmitted through the tongue 30, rib 27 andsheet 2 into the water in the boiler. At times when steam is flowingthrough the unit some heat is similarly transmitted to the boiler waterbut not sufficient to impair the superheating efiiciency of the unit.

The inner tube 21v is kept in proper spaced relation to the outer tube23 by means of suitable supports or spacers 3232 which are preferablywelded to the inner tube as shown in Fig. 6.

It is usually necessary in. locomotives to use auxiliary draft meanswhen the main throttle is closed and there is no exhaust steam from themain engine to create the draft in the ordinary way. At such times thereis of course no steam flowing through the superheater elements but therewill be a substantial amount of gases flowing through the fines. Inorder to protect the radiant units, which are most in need ofprotection, against damage from gas flowing through the fines in whichthey lie, I prefer to provide damper means which make it possible toshut oil gas flow through those flues in which the units 7-17 arelocated. For this purpose the front ends of the fines, in which theelements 17--17 lie, open into a space defined by the partition 33. Thispartition has on each side a damper 3 1 (only one being shown, see Fig.3). These dampers are secured to and operated by means of the shaft Thisshaft is actuated in any preferred manner, either manually orautomatically. When the damper 34 is closed, the gas flow through thelines in which the units 17-17 are located is shut off, the units beingthereby protected.

In the form of the invention illustrated in Figs. 1 to 6 and justdescribed, the radiant ele ments are of the Field-tube type. It ishowever iot necessary that they be given this form and the second formor my invention shown in 7 to 13 uses elements of the ordinary hairpinloop type. In this variation of my invention, the eler -ents located inthe fire-box do not extenc. forward through the fines 55 but extendoutward through water leg 34. For this purpose thimbles 3535 of suitableshape are provided which secured to the two sheets making up the waterleg. Each element comprises two legs 1' 36-46 united in the front by areturn bend 37. The ends which extend through the thiznbles 35 are benttoward and connected to the bi-chambored header 38. One end of eachelement coininunicates with the chamber ll and the other with chamber4%.

Steam is admitted to one of the chambers, for example 40, by means aconnection 42 and leaves the other chamber by means of neck 43. Thepipes 44 and 45 respec-- tively supply and take away the steam. Theelements of this form of super-heater supported and protected by meansquite similar to those used in the i rm first described. Aweb or lib 27ais welded along one edge to the sheet 2 as at 2812. a tongue 30aslidably engages the dove-tailed groove. This tongue is secured in goodheat transferring relation, as by welding, to the two tubes 36-36 of theunit. Preferably the web or rib 27a is also made in sections spacedapart as at 31a-3la.

The thimbles 35 are of such shape that the space between them and thepipes 36-36 is easily closed up if desired.

It will be understood that the steam supplied to this radiantsuperheater shown in Figs. 7 to 13 may, if preferred, be given apreliminary superheat in a flue superheater of the ordinary type or anypreferred form, or that in some cases the radiant superheater is theonly superheater used.

The type of superheater element shown in Figs. 9, 12, and 13 may ifpreferred also be used in the form of my invention first described, andsimilarly the Field-tube unit may be used in the second form. Furthervariations will occur in Its outer edge is dove-tailed at 29a and thesheet, a superheater comprising a tubular ele-- ment in proximity to thesheet, and means to protect said tubular element against over-heatingcomprising a web secured to the sheet and to the tubular element tosupport the latter and to conduct heat from it to the sheet.

2. The combination claimed in claim 1, the web extending in the samedirection as the tubular element and the connection between the twobeing such that it permits longitudinal relative motion.

3. In apparatus or" the class described, the combination of a fire-boxhaving a water-cooled crown sheet, a superheater comprising a pluralityof tubular elements in generally parallel arrangement in proximity ofthe crown sheet, and means to protect said elements against overheatingcomprising a web for each element extending between the crown sheet andthe element and connecting the two in heat-transferring relation.

4. In a locomotive boiler having a fire-box with a water-cooled crownsheet, a smoke-box, and fiues connecting the two, the combination of asuper-heater header in the upper part of the smoke-box, a plurality oftubular superheater elements with their ends connected to the header andextending through the fiues into the firebox to a point in proximity ofthe wall opposite the fire-box flue sheet, and means to protect theportions of said elements which are located in the fire-box againstover-heating comprising a web for each element extending between it andthe crown sheet, parallel to the element, and connected in heattransferring relation to the element and to the crown sheet. I

5. The combination ccording to claim 4 and including further additionalmeans to superheat the steam before it is delivered to the saidsuperheater header and comprising tubular elements located in otherlines.

6. Apparatus in accordance with claim 1, the

tubular element comprising an outer tube closed at one end and an innertube located within the former and spaced from its wall and having anopen end adjacent'to the closed end of the former, and means to supplysteam to the opposite end of one of the two tubes and to take away steamfrom the opposite end of the other.

7. The combination according to claim 1, the

tubular element comprising an outer tube closed at one end and an innertube located within the former and spaced from its wall and having anopen end adjacent to the closed end of the former, and means to supplysteam to the opposite end of one of the two tubes and to take away steamfrom the opposite end of the other, the web extending in the samedirection as the tubular element and being welded to the sheet andsecured to the outer tube by a dove-tail tongueand-groove jointpermitting longitudinal relative motion. v

8. In apparatus of the class described, the combination of a fire-boxhaving a Water-cooled crown sheet and a rear water leg, a plurality ofthimbles extending through the water leg, a superheater header adjacentto the outside of the water leg, a plurality of tubular superheaterelements connected to the header and extending through the thimbles andalong the crown sheet, and means to protect these elements againstover-heating comprising a web for each element extending lengthwise ofthe element between it and the crown sheet and connecting the two inheat-transferring relation and so as to support the element.

9. The combination according to claim 1, the web extending in the samedirection as the tubular element and the connection between the twobeing such that it permits longitudinal relative motion, and that theelement can be removed by moving it in a longitudinal direction.

10. In a locomotive boiler the combination of a furnace including awater-cooled wall, a primary superheater of the smoke flue typecomprising tubular elements disposed in the path of flow from thefurnace, at superheater exposed to furnace radiation serially connectedto the primary superheater and comprising tubular elements extendinginto the furnace adjacent to said wall, a header to which the tubularelements of both of the superheaters are connected, and provisionscommon to the wall and the radiant superheater elements to pass excessheat from the latter to the Wall.

'RUDOLF M. OSTERMANN.

